Process of making tappets



Sept. 1, 1925.

1 w. D. BARTLETT ET AL PROCESS OF MAKING TAPPETS Filed May 23,

l Arromws'f Patented Sept.` 1, 19,25.

j UNITED STATES 1,551,631 PATENT OFFICE.

WILLIAM D. BARTLETT AND WILLIAM SPIRE, F CLEVELAND, OHIO, AS'SIGN'ORS TO THE STEEL PRODUCTS COMPANY, O'F CLEVELAND,OHIO, A CORPORATION 0F omo.

PROCESS ,OF MAKING TAPPETS.

\' Application mea may 23, 1923. semina.' 640,855.

y To all whom t may concern:

Be it known that we, WILLIAM D. BART-4 Ln'rr and WILLIAM H. Srma, citizens of the interna a method of making same.

Said invention has for its object, the provision of an element of the above described character which will be economicalof manufacture and eflicient in the performance of itsfunction, andconsists of a structure'andy method'hereinafter fullydescribed and particularly set forth in the claims.

More specifically our invention consists of a method and structure produced there- 4 by, which method consists of weldingto a steel blank of a character suitable for formf ing the tappet stem, a blank'of steel ofia character. diierent from that ofthe stem and such as will provide .a wearing surface caypable of resistingeiliciently the wear' `to which deforming the end of the structure so rothe element is to be subjected; then duced so as to vform the required hea of which the wear-resisting metal willnform a part of the contact surface.

The annexed drawing and the following description set forth in detail a method and means embotying our invention as applied to the manu acture of a tappet,.such disclosure, however, constituting but one of various ways in which the principles of our invention may be a plied. i

In said annexed rawing: Fig. 1 represents a side elevation of two unjoined -blanks used in producing a tappet in accordance with' our invention.

Fi 2 represents said two blanks after the ave been welded, showing also the die an plun er in axial section and in the positions wich they occupy prior to the 'upf setting operation.

Fig. 3 represents the tappet structure and an axial section of the die and plunger in residents lof Cleveland,

combustion engines; together with' the positions which they'occupy after the die and plunger have performed the upsetting operation.

One method of carrying out our invention as applied lto tappet manufacture, is to rst take a cylindrical bar 1 or blank of steel of a non-hardeningscharacter, such for instance as a low-carbon steel, of suitable dimensions for'making a tappet of required size, making proper allowance for the final finishing operations. To one end j of this blank is then welded a short cylindrical blank 2v of. a steel susceptible to a hardening process such as4 will' produce thereon a surface of -suiicient hardness to eiiiciently withstand to the-required degree, the wear to which the tappet is to be subjec'ted, as for `instance a high-carbon, ,tool, tungsten or silchrome steel, and to which we refer generally herein as hardening steel. The term non-hardening as 'herein used refers to a steel which when subj ected to a hardening process is incapable of `having imparted thereto a surface of sufficient hardness to efficiently resist the wear to which the tappet is to be subjected.

The structure soformed is then placedin a suitable die 3 formed with a suitable die more, .a portion of the blank 1 is allowed to project into such cavity which is ofreater volume than that of the attached b ank' 2, as shown in Fig. 2. The metalin the die cavity is then .upset by means of a suitable plunger 4.

As a resultrof this upsetting operation the metal of the end of theblank 1 tlows laterally as does also the metalof the blank 2 and ysuch metal of blank 1 also is caused to prround the metal of blank 2 as shown in e die cavity is of a form such as will reduce therrequired shape of headwhich 1nr this case consists of a' diametrically enlarged .flange portion 5 and a fillet portion 6 joined to the stem 7.

whereby the metal insert 8 formed;

blank 2 isl hardened, after whichthe structure maybe subjected to the desired finishing operations of turning, boring, tapping, grmding or polishing7 as will lbe understood.

The'outer 'surface 9 of the insert 8 of the tappet forms the Contact surface which being hard,` efliciently resists the Wear to which the ta-ppet is subjected. Since the area of such surface7 in theillustratedem'- bodiment-of our inxntion, isless than that of the end of the flange portion of the tap;

pet, and the insert is lcentrally located, it is laterally removed from the periphery of said ange portion and hence'aiter being hardenedfneed not `be `subjected to any 'but a grinding or polishing. process.

' "What We claim is:

I Thesteps in a. method ot' forming a 'taippet which consists in Welding to the end tension thereof a metal member of -harden#v ing steel? thenl deforming the-end ofsaid blank and said metal member by an upsetting operation to cause the metal of the blank and of said member to spread laterally into a head faced with themet'al of said member substantially across the end of the head. Y

3. The method of forming a tappet which consists' in Welding to the end of a blank of nonfhardening steel as an extension thereof a metalmember ot' hardening steel, then de# forming the end of said blank and said metal member by an upsetting operation to cause the metal of the blank and of said member to spread laterally into' a head faced with the metal of said membersubstantially across theA end oi' the bead, and

then 'hardening the latter.

4.. The steps in a method of forming a tappet which consists in Welding to the end of a blank a metal member capable of form- -ing a Wear-resisting surface, Ithen 'deforming the end of saidblank and metal member, While held in a die having a recessof the size of the head to be'formed, by pressure 'applied in the direction of the axis of the blank to cause the metal of the blank and lof said metal member to spread laterally into a head `faced With theVV metal of said member substantially. across the .end of the head.

signed by us this 29th 'day of Aprir 1923.

. WILLIAM D. BARTLETT; WILLIAM` H. SPIRE. 

